Inkless recording method



N 1962 E. G. MILLIS INKLESS RECORDING METHOD Filed Dec. 1'7, 1958Patented Nov. 6, 1962 Ware v Filed Dec. 17, 1958, Ser. No. 780,965 2.Claims. (Cl. 346-1) This invention relates to a method of recording andmore particularly to an improved method utilizing a thin stream of fluidissuing from a hollow moving pen and reacting with a chemically treatedrecording medium to form a dye and trace the locus of pen movement.

The recording instruments in common use are usually comprised of a pen,actuated in its movements in accordance with the data to be recorded,which rides on a moving web of paper and deposits an ink trace. Suchinstruments are subjecttothe disadvantage of frictional engagement ofthe pen with the paper causing a drag which opposes the pen movement.This drag materially afiect s' the accuracy of recording so that whenvery precise measurements are necessary, they are unobtainable oncommercial instruments. Efforts have been made to reduce the drag effectand increase the efiiciency of the recorder by removing the pen from therecording paper and blowing a stream of air containing droplets of inkthrough the pen. In another instance, the stream of air contained nosuch printing medium, but instead the pressure of the air stream forceda colored liquid from the paper interstices. In still another instance,the air stream pressed the paper against a marking medium positioned onthe reverse side of the paper. Such eflorts have been subject tonumerous disadvantages including: the frequent clogging of the ink inthe pen passage, the spread of the liquid ink on the paper, thecomplexity of the ap paratus required, the ditficulty of makingnecessary adjustments, and the need for special apparatus and recordingmediums not generally or easily available.

In the instant invention, frictional drag of the pen is eliminated bymoving the pen from the recording paper but the recording trace is verysimply obtained with commercially available materials and commonapparatus only slightly modified. The improved method contemplatesblowing a fine jet of gas through the pen against a recording papertreated with a reagent which chemically reacts with or in the presenceof the gas at the points of impingement to form a dye and leave anaccurate trace of the data to be recorded. The improved methodpreferably uses materials, chemical compositions, and reactionsavailable and known in normal Ozalid or similar processes ofreproduction.

The present most common Ozalid reproduction process is the two componentmethod. In this method, paper or any other suitable base is coated witha solution that contains a light-sensitive stabilized diazo, such asdiazo anhydrides stabilized by employment of metal salt complexes, andan azo coupling component, such as hydroxy derivatives of naphthalene,resorcinal, and the like. The paper is exposed to ultra-violet orfluorescent light under a pattern. Where the pattern is transparent, thelight penetrates the pattern and decomposes the diazo. Where the patternis opaque to light, the diazo remains undecomposed. On treatment of theexposed paper with ammonia vapors or with an alkaline solution, an azodye is formed at those places where the diazo was not destroyed throughcoupling of the residual diazo compound with the coupling component; nodye is formed at those places where the diazo was fixed or burned out.In the method of the present invention the ammonia, captive in a finejet stream, is released under pressure to follow a precise recordinginstrument and form a delicate pattern on the recording paper. The paperis then fixed by decomposing the light-sensitive diazo. This issubstantially a reversal of the Ozalid procedure which first applieslight and then ammonia. Such reversal if applied to normal Ozalidreproduction processes and machines would yield no usable prints.

It is a primary object of the present invention to provide an improvedmethod of recording which will permit more accurate recording results byelimination of the friction of the recording pen or stylus.

Another object of the invention is to provide an inkless method ofrecording which depends upon the immediate chemical reaction of a fluidcarried by the moving pen with a reagent composition coating orimpregnating the recording medium.

A further object of the invention is to provide an improved recordingmethod which is simple in its operation and may be easily carriedoutwith readily available materials and apparatus requiring only slightmodification.

The novel features that are characteristic of the invention are setforth with particularity in the appended claims. The invention itself,however, both as to its on ganization and its method of operation,together with additional objects and advantages thereof, will best beunderstood from the following description of a specific embodiment whenread in connection with the accompanying drawing.

In the attached drawing, the single FIGURE is a diagrammatic sketch withconventional parts omitted of apparatus capable of performing the methodof the present invention, wherein reference numeral 10 indicates a drivedrum of a recording instrument over which is trained a strip ofrecording paper 12. The recording medium 12 is preferably paper coatedwith a diazo emulsion of a yellowish color which reacts with ammonia gasor vapor to form a blue, brown or black dye. The ammonia used in theprocess is contained under pressure in a tank 30 and fed to the hollowpen or stylus 20 by means of flexible rubber or other suitable tubing28. Appropriate controls in the form of valves or stopcocks, not shown,may be inserted in the line to control the pressure and movement of theammonia. The hollow stylus 20 is pivoted for movement about an axis 24according to the force applied by a measuring instrument, and iscounterbalanced by adjustable weight 26 so that it will move inproximity to the paper 12. but without touching the paper. A fine streamof ammonia gas 22 is directed from the stylus 20 against the paper 12and an immediate reaction at the points of impingement of the stream ofammonia is obtained to form the color trace 14 of the movement of thepen. A fan 31 may be simultaneously operated to blow air against thepaper adjacent to the point of the stylus. This dissipates any spreadingammonia vapor so that only the concentrated and thin stream whichstrikes the paper will produce a sensitive and accurate trace of the penmovement, and prevents unwanted blurring by ammonia excess to the jetfrom the pen. Preferably, the paper is subjected to fluorescent orultra-violet light from lamp 32 after the dye trace has been chemicallyformed so that the unreacted portions of the paper are fixed and willnot later discolor as a result of the presence of ammonia in theenvironment or atmosphere to which the paper may be removed.

In performance of the methods with the described apparatus, the velocityof the ammonia jet is first regulated by adjustment of the gas pressure,and the pen is adjusted to float just above the paper by appropriatelysetting the weight 26. The recording instrument is then placed inoperation to move the pen to register the data to be recorded. Theammonia gas is fed from tank 30 through the stylus 20 and from its openend, in a fine stream, to the paper 12. A practically instantaneouschemical reaction occurs in the paper coating at the points ofimpingement of the ammonia jet to discolor the paper and leave a colortrace. The instrument drum 10 moves the paper at a proper speed so thata continuous and precise trace 14 of the data being recorded by thestylus 20 is obtained. During the operation, the fan 31 dissipates theammonia vapor not used in the reaction with the paper coating. Theultra-violet light from lamp 32 fixes the unreacted portions of thepaper by decomposing the diazo in the coating. it has been found thatexcellent results are obtained with a relatively low pressure of about 5pounds per square inch of the ammonia gas to write at speeds up to about1 per second on the paper. Higher pressure will allow a higher rate ofspeed.

It is evident that only slight modification of commercially availablerecording instruments is necessary to practice the instant invention,e.g., the addition of the ammonia tank and control, and the provisionfor adjustment of the pen away from the paper. The paper is commerciallyavailable and is used in Ozalid processes. The ammonia gas is alsocommercially available. Thus, the improved method may be utilized withlittle difiiculty or expense.

Although a movable recording element or pen has been described, it willbe understood that the data may be recorded in the same manner with afixed recording element provided the record medium is moved inaccordance with the data to be recorded. If desired, an alkalinesolution may be utilized in place of the ammonia gas to form the dye onthe recording paper.

Although a certain specific embodiment of the invention has been shownand described, it is obvious that many modifications thereof arepossible. The invention, therefore, is not to be restricted exceptinsofar as is necessitated by the prior art and by the spirit of theappended claims.

What is claimed is:

1. A method of recording data comprising:

(a) supplying a gas under pressure to a hollow recording element inclose proximity to a record treated with a chemical reagent adapted tobe discolored by said gas,

(12) moving said recording element and record relatively withouttouching in accordance with the data to be recorded,

(0) emitting a fine stream of said gas from said recording elementduring said relative movement against said record to react chemicallyand form a thin color trace on said record at the locus of points ofimpingement of said gas,

(d) blowing a stream of air against said record in close proximity tosaid recording element at an area just ahead of said color trace toremove the unreacted portion of said gas therefrom immediately aftercontact and thereby avoiding further chemical reaction and blurring ofsaid color trace, and

(e) immediately ahead of the area where said air is directed againstsaid record exposing said record to an environment to fix said recordfrom any further chemical reaction.

2. The method of claim 1 wherein said gas is ammonia.

References Cited in the tile of this patent UNITED STATES PATENTS462,504 Olan Nov. 3, 1891 1,819,264 Ranger et al Aug. 18, 1931 2,566,443Elmqvust Sept. 4, 1951 2,597,306 Eaton et al May 20, 1952 2,739,029Pollard et al Mar. 20, 1956 2,862,782 Cann Dec. 2, 1958

